We will continue our studies of the properties of the glucagon binding protein which we have solubilized and purified from rat liver plasma membranes; further purification, determination of specificity, and coupling of the glucagon "receptor" to solubilized adenylate cyclase are among the studies of interest. We will begin the isolation and purification of the rat brain synaptic membrane receptors for dopamine and nonepinephrine following completion of our studies on the interaction of these putative chemoneurotransmitters with particulate synaptic membrane receptors. We will undertake to identify prostaglandin and ACTH receptors in the plasma membranes of appropriate target tissue cells.